The short answer is YES, but if you're interested in more detail, I gave a paper at the 49th ASA/CAA in Vancouver, 119th AES in NYC, and 23rd VDT in Leipzig titled "Physiological and content considerations for a second low frequency channel for bass management, subwoofers, and LFE" with the following abstract:

By convention, "frequencies below 90Hz produce no interaural cues useful for spatial sound or localization." Yet some claim they are able to hear a difference between a single subwoofer channel (whether or not to more than one subwoofer) and two ("stereo bass"). Reported research supports the Jeffress model of interaural time difference (ITD) determination in brain structures, and extending the accepted lower frequency limit of interaural phase difference (IPD). Meanwhile, uncorrelated very low frequencies (VLF <100Hz) exist in nearly all existing multi-channel music and movie content. The audibility, recording, and reproduction of uncorrelated VLF are explored in theory and experiments.

The full paper is the second .pdf down at http://www.filmaker.com/papers.htm. As Howard mentioned, the objective of these experiments, as with the Ambiophonic DSP plug-in, was to extract every nuance of perception, enjoyment, and realism from ordinary stereo recordings - and for extraordinary electronic music!_________________Robin Miller

The short answer is YES, but if you're interested in more detail, I gave a paper at the 49th ASA/CAA in Vancouver, 119th AES in NYC, and 23rd VDT in Leipzig titled "Physiological and content considerations for a second low frequency channel for bass management, subwoofers, and LFE" with the following abstract:

By convention, "frequencies below 90Hz produce no interaural cues useful for spatial sound or localization." Yet some claim they are able to hear a difference between a single subwoofer channel (whether or not to more than one subwoofer) and two ("stereo bass"). Reported research supports the Jeffress model of interaural time difference (ITD) determination in brain structures, and extending the accepted lower frequency limit of interaural phase difference (IPD). Meanwhile, uncorrelated very low frequencies (VLF <100Hz) exist in nearly all existing multi-channel music and movie content. The audibility, recording, and reproduction of uncorrelated VLF are explored in theory and experiments.

The full paper is the second .pdf down at http://www.filmaker.com/papers.htm. As Howard mentioned, the objective of these experiments, as with the Ambiophonic DSP plug-in, was to extract every nuance of perception, enjoyment, and realism from ordinary stereo recordings - and for extraordinary electronic music!

Thanks rmiller. By dual subwoofer are you referring to a "stereo bass" setup (i.e. each subwoofer is reproducing bass for left and right channels respectively or for front and back in a 5.1 setup?) or to a dual "mono bass" in which all channels are added and redirected to two subwoofers reproducing identical content?

So, there is not any problem in applying ambio to the bass (20-80hz region) and redirecting that signal (carrying the originals and inverted pairs singals) to even an unique subwoofer?

To all interested in Ambiophonic DSP, I received a couple more private communications that I'll share here to help others...

1) One with a surprising statement: that mostly he "prefered monaural to stereo for music listening!" Surprising as this statement is to me, I believe there is a simple explanation - this person likely has been long-disappointed by the lack of a compelling difference, or the artifacts, of conventional stereo (and had not yet tried Ambiophonics' fix). I suggested as an experiment he take 5 minutes to play the Ambiophonic DSP demonstration at www.filmaker.com/products.htm on a PC (or better yet hook your PC/laptop to your stereo); that he might experience the sense that stereo is not delivering immediately go away. That his perception of a very wide soundstage would place ambience (even artificial reverberation) toward the edges - perhaps for the first time delivering spacious envelopment not possible with monaural (because we hear differences between our two ears whether listening live or to a recording). Yet as with monaural, there is no "hole in the middle." If his setup were working, his listening experience with Ambiophonics would be radically different from then on.

2) Another reported his laptop sounded "OK" by itself, but it didn't work at all when connected to his home stereo (decent Onkyo receiver and JBL speakers). His speakers were laid down on a shelf (tweeter aside woofer instead of atop as the manufacturer intended, thereby creating phase, dispersion, and image problems), and close together inside a TV cabinet, so that his normal stereo listening experience was nearly monaural. I suggested he try pulling the speakers out, set them vertical and even closer together, and calibrate his channels (download the "Left/Right/Center" recording at www.filmaker.com/products.htm) at least by ear if he didn't have a sound meter. Voila! he found one channel weak; when balanced, the demo recording came alive, with sound extending way beyond the TV cabinet. He installed the plug-in and will be listening happily every after. - Robin_________________Robin Miller

I have used Virtual Audio Cable myself and unfortunately those drop outs and clicks are apparently par for the course. I'm looking into using Jack for windows and if I come up with good results I'll post it.

Hi Mosc,

Any update in the Jack setup for windows? I've been experimenting changing CPU priority and core affinity for both the player and the VST host but I'm still experimenting some occasional audio drop-outs when using Virtual Audio Cable and ASIO.

Any news on fixing the bug with the delay setting of the pluging when used in VST hosts? Its a little anoying to have to set it manually every time the system starts.

The more we look at jack the less it looks like a solution because it works with "jackified" applications. So, VAC may still be your best bet. The dropout problem is probably related to that, unfortuantely.

As for storing the delay for restart, no solution for that yet, but we are still looking into it.

The more we look at jack the less it looks like a solution because it works with "jackified" applications. So, VAC may still be your best bet. The dropout problem is probably related to that, unfortuantely.

As for storing the delay for restart, no solution for that yet, but we are still looking into it.

What delay do you use? BTW.

Thanks Mosc,

I re-placed my front speakers to a 20 degree angle so I'm using a front delay of 89 us. Back speakers have a higher angle (around 40º) as they are fixed in the wall. I'm using a 160 us delay.

So what kind of music are you listening to and how do you like the results?

Since I placed the front speakers close together and ajusted the delay, ambiophonics result in the most dramatic improvement since I applied DRC. Now, I'm using a dual stereo setup (attenuated signal feed also to the back channels) for stereo music and the results are very pleasing. An almost 180º soundstage and a very clear center mix, after ajusting the zentrum parameter using a SPL meter and the LRC test signal. Certainly the center channel is no more needed and voices are cristal clear. I've being testing all kind of music from pop to classical and arrived to a compromise in the parameters with the "space" set to 6. Above that, the sound becomes too "full" and a little fuzzy, below 5 it loses some o the "punch" in some "dry" recordings and it becomes a little thin.

I've also tried many movie soundtracks with a 4.2 dual ambio setup feed with the 5.1 signal using the same parameters. Results are also impressive with a solid 360º soundfield, except from the occasional drop-outs caused by the rewire process. Again, even without using the center and back channels the mono mixes are very present and clear. Speakers "dissapear" when lights are off.

Now and then I come across more and more references to ambiophonics and I think they were from early impressions.

For example Siegfried Linkwitz? I know he references it several times on his site.

Quote:

I find DSP that cancels loudspeaker cross-talk at the two ears impressive at first, but it becomes quickly 'phasey' and artificial. Headphone listening is artificial in spatial terms. DSP for ambience recovery from 2-channel recordings and with four additional speakers for playback lasted longer for me, but the speakers have now all been converted to PLUTO and are put to different use. None of my previous playback systems conveyed the sense of naturalness that the present ORION++ has. It differentiates recordings even more and mostly for the better.

All this makes me wonder about the efficacy of room equalization. I think DSP is in for a fight with ESP and not just with physics.

I have also talked to Tom Nousaine about it briefly and he had heard an early version of it from Ralph and made the comment it never really worked the way it had been promised.

I cringe at calling it promotion, but do you ever branch out and try to offer demos to certain celebrities to see what their current thoughts are on the newest concept? The reason I ask is because I have to agree with the statements from the convolution method but feel the new version is not like that.

...ambiophonics result in the most dramatic improvement...An almost 180º soundstage and a very clear center mix, after adjusting the "Zentrum" parameter using a SPL meter and the LRC test signal [see www.filmaker.com/products.htm]. Certainly the center channel is no more needed and voices are crystal clear...I've being testing all kinds of music from pop to classical and arrived at..."Space" set to 6. I've also tried many movie soundtracks with a 4.2 dual ambio ["PanAmbio" surround] setup fed with the 5.1 signal...Results are also impressive with a solid 360º...

...and (re Linkwitz and Nousaine comments about early Ambio solutions)...

Quote:

I have to agree with the statements from the [earlier] convolution method, but feel the new version [Ambiophonic VST] is not like that.

Thanks to janderclander14 & durwood for your feedback. As the developer of the earlier RACE encoders, I can attest that this latest Ambiophonic VST plug-in is the result of a great deal of work to make it best of breed. We invite other users to comment on how it changes the way you experience stereo or surround music, movies, or games._________________Robin Miller

As for storing the delay for restart, no solution for that yet, but we are still looking into it.

I was wondering if, as a temporal solution, could it be possible to change the default delay value of the dll by maybe changing a windows registry key or some file?. I've put the speakers in the definitive location and I only need that all the plug-in dll instances load with a fixed delay value.

Received a personal e-mail from a user in Switzerland who tried the several available Ambiophonic solutions and proclaimed AmbioDSP “my favourite Ambio plugin, which is well worth the money!” (Hope he posts directly on this forum more of his helpful findings.)_________________Robin Miller

The AmbiophonicDSP is not tailored for live music. It's great for mixing and mastering. I worked on this to provide a better way to listen to electronic music._________________--Howard
my music and other stuff

I finally have the plug-in running. Thanks for your response to my several emails. Using the little SaviHost application you recommended is way better than Winamp. No hassle and no need for Virtual Audio Cable. I`m using my external CD player as a source.
The sound of AmbioDSP is astonishing, period.
I am looking for some affordable VST-capable hardware that I could use for this purpose instead of a computer. If somebody is exploring this route I would like to hear from them.

Why not go back in time and find a Carver Sonic Hologram Generator C-9? It would be interesting to compare the plugin to it.

I have a friend who has one of the Carver Sonic Hologram Generators. I think it dates back to the 1980s. For its time, it was really fantastic, but in AB comparisons, the AmbiophonicsDSP is much better. It provides a more accurate spacial stage and has less distortion. (Of course, I'm biased). But still, the Carver unit uses analog delays (not bucket brigades) which are frequency dependent. I'm sure Mr. Carver used multiple delays for multiple frequencies bands to minimize this problem, but it's still only an approximate technique.

Still, Carver is a superb designer. No one else in those days even attempted such a device. If you can pick up any piece of vintage Carver gear, it would be sweet, IMHO._________________--Howard
my music and other stuff

Posted: Wed Sep 01, 2010 5:38 am Post subject:
I think a cheap PC is still the most affordable route.

Indeed, a cheap PC is the best alternative overall but fan noise puts me off. Tried a mini laptop but it was noisy as well.

For those of us using ambiophonic software with four channel sources a four channel ambio would be a great enhancement: with the current configuration you need to have two windows open on the screen and then assign the appropiate input and output devices for front and back, but sometimes the selection in one of the windows seems to have effect on both and it can get a bit tedious to have it ready to go.

I find that the high frequencies- 6Khz or so onwards- are not efficiently cancelled so they seem to always come from where the speakers are. After intensive listening I find this to be a fact both in your as well as Stephan Hotto´s software. I am now testing a thin and long absorbing element between the tweeters and extending to the listening position as a way to overcome this. Results are satisfactory so far and, for someone who has been living with a full sized barrier for years, still a huge improvement.

I´ll try to post a picture next week (I have no camera, need to borrow one). It is just one of those fiberglass insulation cilinders that wrap around water pipes, 9" in diameter, extending from between the tweeters towards my head. [img]http://expressinsulation.com/fiberglass_insulation.html[/img]
Physical barriers themselves do not cancel crosstalk as effectively up there as in the lower frequencies either, but highs sound better integrated with the rest than in the software solution alone. Combining both could be a good solution. Time and further listening and testing will tell.

The four-channel dsp could be a duplicate of the current window with one single device selection fold-up showing input and output devices for front and rear channels.
In the current configuration you open the device selection fold-up for one of the windows and do your delection, then you open the other, which hides the previous, and do your selection. I´ve found that this last selection may have modified the previous one, but you never now for sure since only one device selection fold-up is open at a time. So you need to play some music and find wether it is o.k or it got fouled up and both engines are proccessing the front channels (or the backs).

After tinkering with the partial barrier for high frequencies I have decided it will not stay. The artifacts I heard in the higher range were a result of too much recursion. I have also toyed with RACE in Audiomulch but prefered your implementation. You have done a very good job with your Ambiophonic DSP.
It takes months of experimentation with the different parameters and physical positioning of speakers and listening chair to really bring out its best.
One issue I have noticed lately is, while using two Ambios for front and back, one will fall out of sync with the other after a short while. Fixing this issue is a priority in my opinion. Just disregard the petty foibles I picked in my previous post, they were more a result of my akwardness as a user rather than the software´s shortcomings.

I personally wasn't able to get the high frequency problems you mentioned. But, for sure, too much recurrsion is a distortion maker. We could well have limited the knob to max out at 30%, but we like to hear what's happening in the extremes so as to better understand the subtler effects. I prefer to use the Space control over the recursion knob.

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